There's a thread on kboards about how Michael Sullivan wasn't able to negotiate audio rights as part of standard contract negotiations. Apparently, audio is non-negotiable as far as trad-pub is concerned. The thread goes on for a few pages of speculation before Sullivan himself shows up to clear up some of the confusion. It's some "good to know" stuff, so check it out:
Sullivan is the author of the Riyria fantasy series. (And yes, I totally misspelled Riyria on my first attempt. I had to look it up. Lol...)
The takeaway from his experience: trad-pub wants All The Things from authors who don't know any better, and they're less likely to negotiate now than they were a few years ago.